深圳梅林仙湖苏铁野生种群遗传多样性ISSR分析

仙湖苏铁Cycas fairylakeaD.Y.W ang是国家濒危保护植物,目前仅在我国广东省深圳市和曲江县发现有自然分布,个体总数已不足2 000株。本文应用ISSR标记对深圳梅林郊野公园仙湖苏铁野生种群的遗传多样性进行了研究。从100个引物中筛选出10个用于正式扩增,在14个个体中共检测到77个清晰的扩增位点,其中多态性位点67个,多态位点百分率为87.01%。根据所得数据求出的观察等位基因数为1.870 1,有效等位基因数为1.356 8,Ne i基因多样性指数为0.219 6,Shannon多样性指数为0.344 5。与其他苏铁类植物和濒危植物相比,仙湖苏铁仍然保持很高的遗传多样性水平。基于Jaccard相似性系数的UPGMA树系图表明,梅林郊野公园的仙湖苏铁个体明显地分为2个亚群,ISSR表型特征的主成分分析(PCA)也支持了聚类分析结果。研究结果对仙湖苏铁的保育和管理具有重要意义。

Genetic Variation in the Endemic Plant Cycas fairylakea(Cycadaceae) from Meilin Forest Park in Shenzhen on the Basis of ISSR Analysis

Cycas fairylakea D.Y.Wang is a rare and endangered cycad species narrowly distributed in Guangdong,China,only with no more than 2000 individuals.ISSR markers were used to assess the genetic variations of Cycas fairylakea from Meilin Forest Park in Shenzhen.The species exhibits a higher level of genetic diversity compared with other cycads and the relative endanger plants.Ten ISSR primers detected 77 sites,out of which 67(87.01%) were polymorphic loci.Number of observed alleles was 1.8701,number of effective alleles was 1.3568,Nei's gene diversity was 0.2196,and Shannon index was 0.3445.UPGMA tree based on Jaccard similarity coefficients exhibited that 14 individuals were clustered into two subgroups,which was supported by a principle components analysis(PCA) of ISSR phenotypic data.On the basis of these results,strategies were suggested for the conservation and management of the species.